EP2202732A1 - Vorrichtung und Verfahren zum Lesen und Vorrichtung zum Lesen und Schreiben von Hologrammen - Google Patents

Vorrichtung und Verfahren zum Lesen und Vorrichtung zum Lesen und Schreiben von Hologrammen Download PDF

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Publication number
EP2202732A1
EP2202732A1 EP08306008A EP08306008A EP2202732A1 EP 2202732 A1 EP2202732 A1 EP 2202732A1 EP 08306008 A EP08306008 A EP 08306008A EP 08306008 A EP08306008 A EP 08306008A EP 2202732 A1 EP2202732 A1 EP 2202732A1
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EP
European Patent Office
Prior art keywords
coherence length
reference beam
holographic storage
storage medium
hologram
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP08306008A
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English (en)
French (fr)
Inventor
Joachim Knittel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thomson Licensing SAS
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Thomson Licensing SAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Thomson Licensing SAS filed Critical Thomson Licensing SAS
Priority to EP08306008A priority Critical patent/EP2202732A1/de
Priority to TW098141084A priority patent/TW201025318A/zh
Priority to US12/653,241 priority patent/US8437060B2/en
Priority to EP09179170.7A priority patent/EP2202735B1/de
Priority to KR1020090129241A priority patent/KR20100074067A/ko
Priority to CN2009102619477A priority patent/CN101877229A/zh
Priority to JP2009292150A priority patent/JP2010153023A/ja
Publication of EP2202732A1 publication Critical patent/EP2202732A1/de
Withdrawn legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
    • G11B7/0065—Recording, reproducing or erasing by using optical interference patterns, e.g. holograms
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/02—Details of features involved during the holographic process; Replication of holograms without interference recording
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/04—Processes or apparatus for producing holograms
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/22—Processes or apparatus for obtaining an optical image from holograms
    • G03H1/2286—Particular reconstruction light ; Beam properties
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/083—Disposition or mounting of heads or light sources relatively to record carriers relative to record carriers storing information in the form of optical interference patterns, e.g. holograms
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/085—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam into, or out of, its operative position or across tracks, otherwise than during the transducing operation, e.g. for adjustment or preliminary positioning or track change or selection
    • G11B7/08547—Arrangements for positioning the light beam only without moving the head, e.g. using static electro-optical elements
    • G11B7/08564—Arrangements for positioning the light beam only without moving the head, e.g. using static electro-optical elements using galvanomirrors
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/125—Optical beam sources therefor, e.g. laser control circuitry specially adapted for optical storage devices; Modulators, e.g. means for controlling the size or intensity of optical spots or optical traces
    • G11B7/127—Lasers; Multiple laser arrays
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
    • G11B7/1362—Mirrors
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
    • G11B7/1365—Separate or integrated refractive elements, e.g. wave plates
    • G11B7/1369—Active plates, e.g. liquid crystal panels or electrostrictive elements
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/04—Processes or apparatus for producing holograms
    • G03H1/0486—Improving or monitoring the quality of the record, e.g. by compensating distortions, aberrations
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/02—Details of features involved during the holographic process; Replication of holograms without interference recording
    • G03H2001/0208—Individual components other than the hologram
    • G03H2001/0212—Light sources or light beam properties
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H2222/00—Light sources or light beam properties
    • G03H2222/20—Coherence of the light source
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
    • H01S5/065—Mode locking; Mode suppression; Mode selection ; Self pulsating
    • H01S5/0651—Mode control
    • H01S5/0652—Coherence lowering or collapse, e.g. multimode emission by additional input or modulation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H01S5/14—External cavity lasers

Definitions

  • the present invention relates to an apparatus and a method for reading data holograms from a holographic storage medium and to an apparatus for reading data holograms from and writing data holograms to a holographic storage medium.
  • holographic data storage digital data is stored by recording the interference pattern produced by the superposition of two coherent laser beams.
  • one beam the so-called "object beam”
  • SLM spatial light modulator
  • the second beam serves as a reference beam.
  • the interference pattern leads to a modification of specific properties of the storage material, which depend on the local intensity of the interference pattern.
  • Reading of a recorded hologram is performed by illuminating the hologram with the reference beam using the same conditions as during recording. This results in the reconstruction of the recorded object beam, the so called reconstructed object beam that is detected by a detector array.
  • holographic data storage is an increased data capacity per volume and a higher data transfer rate.
  • data is stored as data pages.
  • a data page consists of a matrix of light-dark-patterns, i.e. a two dimensional binary array or an array of grey values, which code multiple bits. This allows to achieve an increased data rate in addition to the increased data storage density.
  • holographic data storage media In holographic data storage media the volume of the medium is used for storing data instead of a layer. Further, the volume of the material used for data storage is not completely exhausted when data is written to it.
  • the advantage of holographic data storage is the possibility to store multiple data in the same volume. This is achieved e.g. by changing the angle between the object beam and the reference beam, called angle multiplexing.
  • angle multiplexing A further option, called shift multiplexing, applies a slight shift between subsequent holograms, which do overlap each other for the most part. Shift multiplexing is performed e.g. by movement of the storage material.
  • the reconstructed object beam suffers under interference effects with stray light inside the optical setup of the apparatus for holographic data stage.
  • the result of such interference effects is a disturbed reconstructed object beam that in turn leads to data readout errors.
  • an apparatus for reading and writing holograms from and to a holographic storage material uses an object beam and a reference beam both having a first coherence length, and that are guided along separate optical branches of an optical setup to be imaged to the holographic storage medium.
  • Said apparatus comprises means for reducing the coherence length of the reference beam to a second coherence length for reading out a hologram from the holographic storage medium, wherein the second coherence length is shorter than the first coherence length.
  • a hologram is generated by constructive and destructive interference of an object beam and a reference beam. Interference effects can only be observed for coherent laser beams, i.e. the coherence length of interfering beams should be larger or equal than the optical path difference between the two interfering beams.
  • the coherence length used in the writing process is called a first coherence length.
  • a laser beam with a second coherence length is used.
  • the coherence length is set to a second coherence length that is shorter than the first coherence length used for writing the hologram. Consequently, interference effects between stray light caused by reflections of the reference beam inside the optical setup and the reconstructed object beam are significantly reduced.
  • the apparatus for reading and writing holograms is advantageous because data read-out errors are significantly reduced.
  • interference between two coherent beams of equal intensity results in a beam showing a four times higher peak intensity than the original beams, in case of complete constructive interference.
  • the coherence length of two laser beams is too low to cause interference effects, the superposition of the two laser beams leads to the mere sum of the intensities.
  • the stray light and the reconstructed object beam that are superpositioned result in the mere sum of the respective intensities in contrast to a possible quadratic intensity super elevation in case of coherent interference.
  • interference results in pixel errors, i.e. data bit errors, due to the fact that it is possible that the intensity of a single or a couple of pixels of a data page is changed due to constructive or destructive interference with coherent stray light.
  • pixel errors i.e. data bit errors
  • the effect is significantly weaker.
  • the second coherence length is lower or equal than a distance between the hologram inside the holographic storage medium and the nearest optical surface outside said holographic storage medium, wherein the distance is determined in the direction of propagation of the object and the reference beam.
  • the first step when considering the emission of stray light is the determination of the optical surfaces reflecting the respective stray light.
  • the coherence length of the reference beam during the read-out process is shorter than the distance from the hologram to the next optical surface, it is impossible for the reconstructed optic beam and said stray light to show constructive or destructive interference effects.
  • the only interaction that is possible is a mere addition of light intensities that, as discussed before, results in an increased background level.
  • the second coherence length i.e. the coherence length used during the read-out process
  • the second coherence length is larger than or equal to a thickness of the holographic storage material, wherein the thickness is determined in a direction of propagation of the object beam and the reference beam.
  • Said apparatus comprises a laser diode for generating a reference beam having a coherence length that is shorter than or equal to a distance between the hologram inside the holographic storage medium and the nearest optical surface outside said holographic storage medium, wherein the distance is determined in the direction of propagation of the object and the reference beam.
  • Said method for reading a hologram from a holographic storage medium applies a reference beam generated by a laser diode, wherein the reference beam has a coherence length that is shorter than or equal to a distance between the data hologram inside the holographic storage medium and a nearest optical surface outside the holographic storage medium. The distance is determined in a direction of propagation of the reference beam.
  • the first step when considering the emission of stray light is the determination of the optical surfaces that cause reflections of the reference beam leading to coherent stray light.
  • the coherence length of the reference beam during the read-out process is shorter than the distance from the hologram to the next optical surface, it is impossible for the reconstructed optic beam and said stray light to show interference effects.
  • the only interaction that is possible is a mere addition of light intensities that as discussed before results in an much weaker effect.
  • holographic data storage digital data is stored by recording the interference pattern generated by two coherent laser beams, the object beam and the reference beam.
  • Fig. 1 shows an exemplary setup of an apparatus 2 for writing and reading holograms to and from a holographic storage medium 20.
  • the apparatus 2 comprises a light source, preferably a laser diode 6 with an external cavity (not shown), emitting a laser beam 1 that is split up by a beam splitter 16 into a reference beam 13 and an object beam 15.
  • the two beams 13, 15 are guided along separate optical branches.
  • a first branch 12 is used to guide the reference beam 13 to the holographic storage medium 20, while the second branch 14 is used for the object beam 15.
  • the coherence length of the laser diode 6 is controlled by a control unit 8 that further controls two shutters 10a, 10b located in the first branch and the second branch 12, 14, respectively.
  • control unit 8 sets the laser diode 6 to a first coherence length and both shutters 10a, 10b are opened, while during the reading process the laser diode 6 is set to a second, shorter coherence length and shutter 10b located in the second branch 14 that is used for the object beam 15 is set to a closed state.
  • the laser diode 6 comprises an external cavity with a mirror (not shown) that is mounted on a piezo-actuator (not shown). Said piezo-actuator is fed with a high frequency modulated drive current during the read-out process of a hologram.
  • the control unit 8 acts as an actuator controller for the piezo-actuator, i.e. a means for reducing the coherence length of the laser diode 6. Due to the fact that the mirror of the cavity is vibrated by the piezo-actuator, the coherence length of the laser diode 6 is reduced.
  • the aforementioned state of operation of the laser diode 6 is called the "low coherence state".
  • a further option to operate the laser diode 6 in the low coherence state is feeding the laser diode 6 with a drive current that is high frequency modulated.
  • the control unit 8 acts as a drive current modulator for the laser diode 6.
  • both shutters 10a, 10b are open and the laser diode 6 is operated in the high coherence state.
  • the laser beam 1 that is emitted by the laser diode 6 is split up into the reference beam 13 traveling along the first branch 12 and the object beam 15 traveling along the second branch 14 by help of a beam splitter 16.
  • the object beam 15 is modulated by a transmissive spatial light modulator 18.
  • a liquid crystal array is used as a spatial light modulator 18.
  • a reflective spatial light modulator in combination with an adapted optical setup can be applied.
  • the object beam 15 and the reference beam 13 interfere inside the holographic storage medium 20. More precisely, the aforementioned beams interfere inside a holographic storage material 4 that is located in the center of a sandwich-like holographic storage medium 20.
  • the configuration of the holographic storage medium 20 will be explained in more detail in connection with Fig. 2 .
  • the coherence length of the laser 6 during the writing process is set to a value that is at least the length difference between the first and second branch 12, 14. This assures that the interference between the reference beam 13 and the object beam 15 at the position of the holographic storage material 4 results in a hologram offering a satisfactory grating strength and contrast.
  • the shutter 10b that is located in the second branch 14 is set to a closed state by the control unit 8. Further, the control unit 8 decreases the coherence length of the laser diode 6 by setting it to one of the aforementioned low coherence operating modes.
  • the low coherent laser beam 1 travels along the first branch 12 to reach the holographic storage medium 20. Due to interference of the reference beam 13 with the hologram stored inside the holographic storage material 4, a reconstructed object beam 22 is generated, which is focused by help of a second beam splitter 24 to an array detector 26.
  • the apparatus 2 shown in Fig. 1 is also able to act as an apparatus 2 for reading only data holograms from the holographic storage medium 20. In that case the second branch 14 used for the guidance of the object beam 15 is completely omitted.
  • Fig. 2 shows a detailed view of the apparatus 2 known from Fig. 1 .
  • the holographic storage medium 20 exhibits a sandwich-like structure of two substrates 28 of about 500 ⁇ m thickness side by side the holographic storage material 4, which has a thickness D of preferably between 100 ⁇ m and 500 ⁇ m.
  • the coherence length of the reference beam 13 used for read-out of the hologram is reduced.
  • the coherence length of the reference beam 13 is shorter than the distance between the hologram and the next optical surface in a direction of propagation of the reference or object beam 13, 15.
  • the coherence length of the reference beam 13 should be shorter than distance S3. The same applies for the distances S1 and S2 corresponding to the distance between the hologram and the surface of the holographic storage medium 20 and the objective lens 30, respectively.
  • the named advantages of the apparatus for reading and writing holograms from and to the holographic storage medium 20 also apply to an apparatus that reads only data holograms from the holographic storage medium 20, as will be explained in more detail with reference to Fig. 3 .
  • the number N of pixels shown in arbitrary units on the ordinate of Fig. 3 is assigned to intensity I also in arbitrary units on the abscissa.
  • Fig. 3 shows the number N of pixels showing a certain intensity I.
  • the left and higher peak 32 indicates the number of dark pixels in a data page, while the right and lower peak 34 corresponds to bright pixels in said data page.
  • a threshold value is set to a certain value I 0 and all pixels below the threshold value I 0 are assumed to be dark, while all pixels above the threshold value I 0 are assumed to be bright.
  • the threshold value I 0 is preferably set to the minimum in the intensity between the higher peak 32, indicating dark pixels and the lower peak 34, indicating bright pixels.
  • a dashed line in Fig. 3 represents the case that the read-out process, in contrary to the aforementioned embodiments, is performed with reference beam 13 that has a high coherence length.
  • the solid line represents the case that the read-out process is performed with reference beam 13 that has a low coherent length.
  • the probability of data readout errors is determined by looking at the number of pixels in the vicinity of the threshold value I 0 .
  • Fig. 3 clearly indicates that in case of a read-out process with a reference beam that shows a high coherence length a larger number of pixels are found around the threshold value I 0 compared to the case the holograms are read-out using a reference beam 13 with a low coherence length.
  • the amount of pixels in the respective area around the threshold value I 0 can clearly be lowered by using a low coherent reference beam 13 for read-out of the data hologram. Therefore, less uncertain data pixels with an intensity that cannot clearly be assigned to be bright or dark is reduced. Consequently, the data read-out error rate is significantly improved.

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  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Holo Graphy (AREA)
  • Optical Recording Or Reproduction (AREA)
  • Optical Head (AREA)
EP08306008A 2008-12-23 2008-12-23 Vorrichtung und Verfahren zum Lesen und Vorrichtung zum Lesen und Schreiben von Hologrammen Withdrawn EP2202732A1 (de)

Priority Applications (7)

Application Number Priority Date Filing Date Title
EP08306008A EP2202732A1 (de) 2008-12-23 2008-12-23 Vorrichtung und Verfahren zum Lesen und Vorrichtung zum Lesen und Schreiben von Hologrammen
TW098141084A TW201025318A (en) 2008-12-23 2009-12-02 Apparatus and method for reading and apparatus for reading and writing holograms
US12/653,241 US8437060B2 (en) 2008-12-23 2009-12-10 Apparatus and method for reading and apparatus for reading and writing holograms
EP09179170.7A EP2202735B1 (de) 2008-12-23 2009-12-15 Vorrichtung und Verfahren zum Lesen und Vorrichtung zum Lesen und Schreiben von Hologrammen
KR1020090129241A KR20100074067A (ko) 2008-12-23 2009-12-22 홀로그램들을 판독하기 위한 장치 및 방법, 그리고 홀로그램들을 판독 및 기입하기 위한 장치
CN2009102619477A CN101877229A (zh) 2008-12-23 2009-12-23 读取全息图的设备和方法以及读取和写入全息图的设备
JP2009292150A JP2010153023A (ja) 2008-12-23 2009-12-24 ホログラム読出装置及びその方法並びにホログラム読出／書込装置

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP08306008A EP2202732A1 (de) 2008-12-23 2008-12-23 Vorrichtung und Verfahren zum Lesen und Vorrichtung zum Lesen und Schreiben von Hologrammen

Publications (1)

Publication Number Publication Date
EP2202732A1 true EP2202732A1 (de) 2010-06-30

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EP08306008A Withdrawn EP2202732A1 (de) 2008-12-23 2008-12-23 Vorrichtung und Verfahren zum Lesen und Vorrichtung zum Lesen und Schreiben von Hologrammen
EP09179170.7A Not-in-force EP2202735B1 (de) 2008-12-23 2009-12-15 Vorrichtung und Verfahren zum Lesen und Vorrichtung zum Lesen und Schreiben von Hologrammen

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US (1) US8437060B2 (de)
EP (2) EP2202732A1 (de)
JP (1) JP2010153023A (de)
KR (1) KR20100074067A (de)
CN (1) CN101877229A (de)
TW (1) TW201025318A (de)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102087504B (zh) * 2011-01-26 2013-03-27 浙江大学 基于单个空间光调制器的光学模式识别器及其方法
JP2014203484A (ja) * 2013-04-05 2014-10-27 株式会社日立エルジーデータストレージ 光情報記録再生装置、および光情報記録再生方法

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CH681117A5 (en) * 1990-02-12 1993-01-15 Oscar Dr Sc Nat Oehler Optical bar coding in hologram form - having hologram optically scanned to provide image projecting onto screen in real object form
US5299035A (en) * 1992-03-25 1994-03-29 University Of Michigan Holographic imaging through scattering media
US20030104285A1 (en) * 2001-09-26 2003-06-05 Kabushiki Kaisha Toshiba Optical recording medium
WO2006118082A1 (ja) * 2005-04-27 2006-11-09 Matsushita Electric Industrial Co., Ltd. 光ヘッド装置および光情報処理装置

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US5416616A (en) * 1990-04-06 1995-05-16 University Of Southern California Incoherent/coherent readout of double angularly multiplexed volume holographic optical elements
DE4202185A1 (de) * 1992-01-28 1993-07-29 Hilti Ag Verfahren zur faseroptischen kraftmessung
US5883875A (en) * 1997-09-02 1999-03-16 International Business Machines Corporation Short coherent-length optical tomograph for high density volume optical data storage devices
EP1769092A4 (de) 2004-06-29 2008-08-06 Europ Nickel Plc Verbesserte auslaugung von grundmetallen

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH681117A5 (en) * 1990-02-12 1993-01-15 Oscar Dr Sc Nat Oehler Optical bar coding in hologram form - having hologram optically scanned to provide image projecting onto screen in real object form
US5299035A (en) * 1992-03-25 1994-03-29 University Of Michigan Holographic imaging through scattering media
US20030104285A1 (en) * 2001-09-26 2003-06-05 Kabushiki Kaisha Toshiba Optical recording medium
WO2006118082A1 (ja) * 2005-04-27 2006-11-09 Matsushita Electric Industrial Co., Ltd. 光ヘッド装置および光情報処理装置
US20090028035A1 (en) * 2005-04-27 2009-01-29 Kousei Sano Optical head device and optical information processing device

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EP2202735B1 (de) 2013-04-10
JP2010153023A (ja) 2010-07-08
TW201025318A (en) 2010-07-01
US8437060B2 (en) 2013-05-07
US20100157401A1 (en) 2010-06-24
CN101877229A (zh) 2010-11-03
EP2202735A1 (de) 2010-06-30
KR20100074067A (ko) 2010-07-01

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